It has heretofore been proposed that closures be provided for containers wherein the closures include a cap that is hinged to the part of the closure on the container by an integral hinge. Conventionally, such closures rely on tension on the hinge to produce a snap action. Typical constructions are shown in U.S. Pat. Nos. 3,628,215, 3,629,901, 3,933,271, 4,047,495, 4,386,714.
Among the objectives of the present invention are to provide a dispensing closure which has a cap that operates with a snap action in moving to and from a closed position; which has minimum hinge protrusion so that it is compatible with high speed filling lines thus allowing greater line speeds; which provides a low profile; which is relatively easier to manufacture; which can be operated by one hand; which has an easy opening pour spout; wherein the spout is self-cleaning and provides a moisture seal.
In accordance with the invention, the closure with a snap type hinge cap comprises a first part adapted to interengage with the open neck of a container, a second part forming a cap and an integral hinge interconnecting the first and second parts. Each of the first and second parts comprises a base wall and a peripheral skirt. A pair of hinge straps extends from the skirts and are positioned on opposite sides of the integral hinge. The radial length of the pair of hinge straps is less than the length of the arc through which the second cap part moves to and from and closed position relative to the first part such that the pair of straps stretch to function as springs. The ends of the pair of straps are attached to the skirts radially inwardly of the periphery of the skirts.
In addition, a preferred form of the invention provides tight seal and spout cleansing features in a closure that is used in a product dispenser. The first part of the closure includes an axial spout extending outwardly therefrom on the top base wall of said first part. The end of the spout is chamfered inwardly. The second part or cap also has a top wall integral with a skirt. On the undersurface of the base wall of the cap are two concentric circular walls spaced apart approximately an amount equal to the wall thickness of the rim end of the spout. The concentric walls are positioned to align with and receive and seal the rim of the spout when the cap is closed. This interrelation provides (1) a tight seal of the spout opening when the cap is closed, and (2) cleansing the spout by having the inner of the concentric walls extending into the spout opening cleansing the spout of product at the top region of the spout each time the cap is closed.